Railroads constitute a major transportation means for moving goods as well as people. However, in order for railroads to operate safely, reliably and inexpensively, it is important to keep their basic infrastructure sound to ensure that the rails are available for service without any down time and are accident free.
Inherently, rails and the fastening systems used to keep the rails in place play a crucial part of the railroad infrastructure and designing such fastening systems requires a lot of interdisciplinary effort between engineers, material science experts and heavy industrial manufacturers because the fastening system must be able to hold the rails in place, with very little tolerance in the position for movement and spacing of the rails as high speed passenger trains, or long and heavy freight trains pass over them.
It has been found that fastening systems consisting of a tie plate resting on a tie or other support and somewhat resilient clips securing each rail to tie plate are advantageous because they can be made reliably with the clips being able to hold on to the rails and resist tremendous linear and rotational forces on the rails. Of course, the retainers used to hold the clips on the plate are subject to the some of the same forces as the clips and must be able to transmit these forces to the tie plate. Until the present invention, these clips were made separately and were then attached to the tie plates by welding, press-fitting or other similar mechanical means. As a result, it was possible for these retainers to separate from the tie plate, in essence making the clips useless.